Vehicles which achieve high relative velocities to the air are preferably designed as aerodynamically favorable to reduce the aerodynamic drag and thus to increase their efficiency. From certain velocity ranges, it can be observed that turbulent boundary layers are generated at higher velocities on surfaces of vehicle fuselage components which protrude directly into the airflow, because of the flow deflection, for example, on leading edges of tail units or wing units of aircraft. The design of these aerodynamic components to reduce the increased aerodynamic drag caused by the boundary layers is not entirely variable because of installation space or functional restrictions connected thereto, however. To reduce the aerodynamic drag because of the turbulent boundary layer, concepts therefore exist of sucking air from areas of tail units and wing units of aircraft which are oriented upstream to reduce the aerodynamic drag, which are currently used only in research aircraft or vehicles, however. The affected vehicle fuselage component is implemented in the form of a tail unit or wing unit front edge having suction openings, which extend from a front delimitation oriented upstream, such as a front edge, up to a front spar of the structure of the tail unit or the wing unit.
In research aircraft in which such sucking of air from a turbulent boundary layer occurs via a vehicle fuselage component having openings, the relevant vehicle fuselage component is typically implemented as a double-walled structure, which is formed by an outer plate and an inner plate. These plates have a constant spacing to one another and are connected to one another by strip-like or tape-like webs. Multiple suction chambers thus result, from which air can be suctioned via the suction openings of the outer plate by applying a partial vacuum or suction. In order to achieve sufficient stiffness of the vehicle fuselage components modified in the above-mentioned way, which must at least correspond to the stiffness of a typical and non-sucking vehicle fuselage component without such suction, a greater plate thickness is necessary or additional stiffening ribs must be introduced, which results in an increased weight of the air-sucking vehicle fuselage component.
In such vehicle fuselage components, in particular in the case of use on aircraft, a low bird strike tolerance results, since the outer plate of the vehicle fuselage component has a weakening of the material because of the suction openings, so that significant denting results upon the impact of birds or other objects, so that the configuration of suction chambers located behind it or even a front spar may be damaged.
EP 1 699 686 A1 and US 2009/0020653 A1 disclose a device for sucking a boundary layer on the surface of an aircraft, in which the suctioned air is supplied to an environmental control system.